Atmospheric Aerosol Deposition on Glaciers in the Cordillera Blanca Mountains of Peru

During the local dry season (June/July) of 2011 and 2012, the American Climber Science Program (organized with the assistance of the American Alpine Club) conducted scientific expeditions in Huascaran National Park in Peru.  The Park is located in the Cordillera Blanca mountain range and contains the world’s largest collection of tropical mountain glaciers.  One component of the environmental research program was sampling particulates on glacier surfaces by means of snow collection and filtration.  Over 150 samples were collected during the two expeditions by volunteer climbers working with scientists in the field.  Glacier snows were collected on over fifteen peaks throughout the range at altitudes from 4800 to nearly 6800 meters.  Snow samples were kept frozen until the climber-scientists returned to basecamp - at which point they were rapidly melted and then immediately filtered through 0.7 micron PallFlex tissuequartz filters.  The particulates captured on the filters have been analyzed for their bulk heat absorption properties as well as to determine the properties of individual particles through X-ray diffraction for bulk mineral identification, and Raman microscopy for chemical mapping of minerals.  Preliminary results indicate that snow age, altitude, as well as geographic location (with respect to urban areas, mines, and predominant wind direction) all play significant roles in the amount and types of contaminants.  Multiple locations were sampled during both expeditions as well as at different times during the same climbing season.  Results include the relative heating capacity of the samples at various wavelengths as well as mineral composition information across the range.  Local weather patterns and geographic observations will be used to identify potential sources of contaminants.  Sampling will continue under the American Climber Science Program in 2013 and beyond.